Electric dry shaver



March l, 1955 JEPSON 2,702,938

ELECTRIC DRY SHAVER Filed Deo. 6, 1950 2 Sheets-Sheet l l /2 P' (j /3 2324. 2.223 24 23 |4 40 NvEN'roR NAR JEPsoN Wm fMuA ATTYs.

March l, 1955 l. .JEPsoN 2,702,938

` ELECTRIC DRY SHAVER Filed Dec, e, 195o 2 snee'ts-sneet 2 fie/' f a 2so 404 l; 3 24- ATTY'S.

United States Patent() 2,702,938 y ELiicrnic par sHAvER Ivar Jepson,OakiPark, Ill., assignor to Sunbeam Corpo-` 3 Claims. (Cl. 30-43) Thisinvenion relates to electric dry shavers, that is, apparatus for use inremoving beards or face hair as well as effecting depilation of hair onthe arms, legs and other portions of the human body.

The electric dry shaver is coming more and more into general use andtoday a substantial percentage of people who shave use electric dryshavers exclusively for this purpose. It has been desirable for .sometime to reduce the shaving time required when using such dry shaverswhile still obtaining a satisfactory shave. In prior copending Jepsonapplication, Serial No. 71,927, filedJanuary 2l, 1949, there isdisclosed and claimed an electric dry shaver which has gone intoextensive commercial use and has been very satisfactory. The electricdry shaver disclosed in the aforementioned Jepson application is a veryfine instrument which is capable of giving long years of excellentservice and consequently is a relatively expensive device embodying thevery satisfactory effectively arcuate cutter and powerful brush typeuniversal motor. There is, however, a market for a somewhat lessexpeiisive, less satisfactory shaver which has a lower manufacturingcost and hence can be sold at a lower price. Although not giving quiteas satisfactory a service, it will excellently serve those who cannotafford the more satisfactory device as shown in the above-entitledapplication. Such an electric dry shaver should be designed so that itmay be held comfortably and conveniently in. the hand of the operatorwithout the requirement of tightly gripping the same as has been thecase prior to the advent of the dry shaver shown in theabove-entitledJepson application. Accordingly,l it is an object of thepresent invention to provide a new and improved electric dry shaver.

It is another object of the present invention to provide a relativelyinexpensive` dry shaver having a greatly increased cutting area so as toreduce the shaving time substantially. i k

Further objects and advantages of the present invention will becomeapparent as the following description proceeds and the features ofnovelty which characterize the invention will be pointed out withparticularity in the claims annexed to and forming a part of thisspecification.

For a better understanding of the present invention, reference may behad to the accompanying drawings in which:

Fig. l is an elevational View with certain portions cut awayillustrating one embodiment of an electric dry shaver incorporatingthepresent invention;

Fig. 2 is an end view looking in the direction of the arrows 2 2 of Fig.l;

Fig. 3 is a sectional view taken on line 3--3 of Fig. 2;

Fig. 4 is a sectional view taken on line 4-4 of Fig. 3, assuming thatFig. 3 shows the complete structure;

Fig. 5 is a fragmentary View of a portion of Fig. 3 in order toillustrate the motor starting means of the present invention;

Fig. 6 is a fragmentary end sectional view of the same portion of theshaver shown in Fig. 5 of the drawings;

Fig. 7 is a schematic circuit diagram illustrating the electric circuitof the dry shaver of the present invention;

Fig. S is a sectional view similar to Fig. 3 illustrating a modificationof the present invention; and

Fig. 9 is a sectional view similar to Fig. 8 illustrating still anothermodification of the present invention.

The electric dry shaver of the present invention generally designated bythe reference `numeral 10 in Figs. 1 to 7 of the drawings is of the typeused in shaving beards and for removing hair from other parts of thebody.

Essentially, theshaver 10 comprises a casing 11 having attached theretoone or more shaver heads 12 extending completely across the longestdimension of the housing or casing 11. The heads 12, two of which areshown in Fig. 4 of the drawings, are provided with the conventionalreciprocating inner cutters 13 which are reciprocated at a relativelyhigh speed by means of a motor generally designated at 14 disposedwithin the casing 11.

The electric dry Shavers available on the market prior to the inventiondisclosed in the above-entitled Jepson application, generally comprisedan elongated casing around which the operators lingers were usuallyclasped in a fairly tight grip to manipulate the shaver. The inventiondisclosed in the above-entitled Jepson application has resulted in theproduction of an electric shaver having a configuration that may readilybe cupped in the hand of the user in a natural manner with the fingersloosely engaging the same. The casing in the aboveentitled Jepsonapplication was of rectangular configuration with the two walls of majorarea substantially square. In the instant application, the same generalconfiguration is involved except that instead of the two walls beingsubstantially square, the outing surface is preferably on the side oredge of the casing having the longest dimension so as to provide themaximum possible cutting surface. With this configuration, the casing 11may be comfortably cupped in the hand with the fingers usually looselyengaging the same as contrasted with the tight grip required of mostusers when holding the elongated casings of prior art Shavers where thefingers of necessity had to encircle the longitudinal axis of thecasing.

As illustrated, the casing 11 of the dry shaver 10 essentially comprisestwo cooperating cup-shaped complementary portions 11a and 11b which areadapted to fit t0- gether to provide a somewhat rectangular-shapedcasing having side walls which approach a square in configuration anddefine a casing having a thickness substantially less than eitherdimension of the side walls. The casing portions 11a and 11b arepreferably molded from a suitable moldable material, many moldableplastic molding materials being readily available on the market for thispurpose providing a smooth and satisfactory appearing surface of anydesired color. If desired, the central portion of the casing 11 which islikely to be engaged by the operators fingers may be provided withslightly raised rib portions or similar deformations in the form of ribsor indentationsvto make it easier to manipulate the dry shaver and forthe additional purpose of providing a more pleasing appearance. Thecomplementary casing sections 11a and 11b are provided with suitableintegral formed portions for accommodating fastening means. Asillustrated, the casing section 11b is proivded with suitable openings16 for receiving fastening screws such as 17 which threadedly engagetapped rib portions i8 defined in complementary casing section 11a. Ifdesired, the tapped rib portions 18 may include threaded metal insertsmolded therein, although with certain plastics available on the market,it may be possible to tap the plastic material directly or mold thethreads directly therein. The casing section 11b is suitably recessed toaccommodate the heads of the fastening means 17 so that they in no wayinterfere with the operators use of the dry shaver 10.

For the purpose of producing the desired cutting action, there areprovided the shaver heads 12, two of which are shown in the drawings,although it should be understood that a single head or more than two maybe employed, depending upon the particular application involved. Asuitable thumb screw 15 is mounted on casing section 11a permittingready attachment and detachment of the heads 12 relative to the casing11. The complementary casing sections 11a and 11b are provided withportions 19 defining an integral ledge or shelf adjacent the head end ofthe dry shaver 10 for supporting thereon a thin somewhat resilient plate20 effectively dividing the dry shaver into a motor chamber and a cutterchamber. This plate 20 is provided with hook-shaped ends 20a forengaging with enclosure members 21 so as to provide a sort of hingedclosure through which access to the cutter com- 3 partment for theremoval of hairs lodged therein during the shaving operation isafforded. Disposed within the cutter chamber upon the plate is a cuttersupport 22 for supporting in a reciprocal manner the one or more innercutters 13. Suitable means specifically illustrated as balls 23 biasedby springs 24 push the reciprocating cutters 13 into shearing engagementwith the shaver heads 12. The cutters and shaver heads are each,provided with suitable openings into which the hairs being cut extend soas to be sheared by the relative reciprocal motion thereof. Theparticular construction of the reciprocating inner cutters and theshaver heads forms no part of the present invention and any satisfactoryelements for this purpose may be employed. However, an important aspectof the present invention is the fact that these cutters and shaver headsextend along substantially one entire side of the casing and, moreover,along the longest dimension of the casing so as to give the maximumcutting area.

In order to reciprocate the one or more cutters 13 associated with theshaver 10, the motor 14 is provided which may be any suitable type ofmotor, but which preferably is of the type disclosed in Jepson andCerveny application Serial No. 142,752, filed February 7, 1950. Asillustrated, the motor 14 is of the so-called impulse type coinprising afield structure made up preferably of a stack of U-shaped laminationsthereby to define a U-shaped field structure. Encircling the base orbight of the field structure 25 is a field coil 26 preferably comprisingan insulating spool 27 having two sections for receiving thereon twolield winding sections 26a and 26b clearly shown in the schematicdiagram of Fig. 7 of the drawings and making up the eld coil 26.Preferably, the spool 27 is formed of two parts of suitable insulatingmaterial capable of being interrelated when placed around the base orbight of the U-shaped field structure 25.

Secured to the field structure 25 are a pair of bearing plates 29 and 30which extend beyond the open end of the U-shaped field structure.Preferably, the bearing plates 29 and 30 are rigidly related to thefield structure 25 in the manner shown in the drawings by suitablescrews or fastening means 31 extending through aligned openings in thesemembers. It will be understood that these fastening means are suitablyinsulated from the laminations through which they extend. To hold theimpulse motor 14 in position within the casing 11, the latter ispreferably provided with tapped openings to receive fastening meanssuch, for example, as the screws 32 rigidly to relate the motor 14 withthe casing 11. The insulating plates 29 and 30 may be formed of anysuitable material such, for example, as a molded plastic such as nylon.These insulating bearing plates, moreover, define suitable bearingswithin which is journalled a crank shaft 35. To the crank shaft 35 issuitably fastened as by set screws or the like an armature 37 formed ofa stack of laminations riveted or otherwise secured together. Thearmature 37 has such a configuration as to provide a two-pole armaturecapable of rotating between the ends'of the U-shaped field structure 25.The longitudinal axis of the crank shaft 35 is disposed parallel to theshort dimension of the casing 10 and perpendicular to each of the longdimensions of the casing 10. The end of the crank shaft 35 extendingbeyond the bearing plate 30 has an elliptical cross section designatedby the reference numeral 35a for controlling the contacts of the impulsemotor to be described hereinafter. The other end of the crank shaft 35extending beyond the bearing plate 29 terminates in a crank comprisingthe eccentric pin 39.

For the purpose of drivingly relating the motor 14 and the reciprocatingcutters 13, there is provided a driving lever 40 attached to a pivot pin41 pivotally mounted in suitable integral ears or projections 29a and30a of the bearing plates 29 and 30, respectively. The driving lever 40is illustrated as effectively comprising a bell crank pivotal about thebearings for pivot pin 41 and the end thereof adjacent the crank shaft35 is provided with an elongated opening 43 for receiving therein thecrank pin 39 whereby rotary movement of the crank shaft 35 causesoscillating movement of bell crank 40 about the bearings for pivot 41.The other arm 40a of bell crank 40 extends through aligned openings 42,43 and 44, respectively, defined in the ledge 19, the plate 20 and thecutter support 22, respectively and an enlarged end thereof is disposedwithin a recess 46 defined adjacent one end of the Gti cutter 13. Wherea plurality of cutters such as are shown in Fig. 4 are employed, aplurality of arms such as 4th: are rigidly attached to the pivot pin 41so as to be oscillated in response to oscillation of the main arm of thebell crank 40 with a resultant reciprocation of the cutters 13.

It will be understood that an impulse motor requires control means forperiodically making and breaking the energization circuit of the fieldWinding sections 26a and 26b. To this end, the bearing plate 30preferably comprises integral projections 49, 50, 51 and 52 formaintaining in position a pair of resilient contact arms 53 and 54, onedisposed on either side of the elliptical portion 35a of the crank shaft35. As illustrated, each of the contact arms 53 and 54 is provided Witha central portion of somewhat circular configuration so as substantiallyto encircle the associated projections 50 and 51, respectively. The endsof these resilient contact arms 53 and 54 remote from the ellipticalportion 35a are provided with a reverse bend to receive therein theprojections 49 and 53, respectively, thereby not only maintaining thecontact arms 53 and 54 in position, but inherently biasing them so thatsuitable contacts 56 and 57 supported from the other ends of the contactarms 53 and 54, respectively, are biased into contacting engagement.Relative separation of the contacts 56 and 57 is caused in response torotation of the elliptical cross section portion 35a which engagessuitable blocks 58 and 59, respectively, of insulating material attachedto the resilient contact arms thereby insulating the latter from themotor shaft 35. When the ends of maximum diameter of the ellipticalportion 35a engage the insulating contact blocks 58 and 59 which,incidentally, may be formed of nylon or other suitable material, thecircuit through contacts 56 and 57 is broken or interrupted. On theother hand, when the elliptical portion 35a of the crank shaft 35 isdisposed so that the ends of its minimum diameter are suitably engagedby the insulating blocks 58 and 59, the contacts 56 and 57 complete anelectrical circuit in the manner clearly apparent from Iig. l of thedrawings. It will be understood that rotation of the crank shaft 35 willcanse alternate making and breaking of the circuit at the contacts 56and 57.

The electrical circuit of the impulse motor of the present invention cannow be considered with reference to Fig. of the drawings where thecircuit elements are schematically illustrated. There are illustrated,contact prongs 60 which effectively comprise the terminals of theelectrical circuit within the motor casing 11 to which may be connecteda conventional power cord or the like for connecting the motor circuitto a source of electrical energy such as a conventional wall outlet.These contact prongs 60 are clearly shown in Figs. 2 and 3 of thedrawings and as illustrated the complementary casing sections 11a and11b are so designed as to define a plug recess 61 within which theprongs are disposed so as to facilitate the connection between theprongs 60 and a power cord not shown. Referring again to Fig. 7, it willbe observed that the prongs 60 are electrically connected by conductors62 and 63 with the terminals of winding sections 26a and 26b,respectively. The other terminals of winding sections 26a and 26h areconnected to the contacts 56 and 57, respectively. It will be apparentthat the circuit through the windings 26a and 26b is alternately madeand broken as the contacts 56 and 57 are engaged and disengaged. Itshould be understood that the impulse motor per se is old and theoperation thereof 1s well understood by those skilled in the art. Thecontacts 56 and 57 close the eld circuit when the armature polesapproach the field or stator poles of the field structure 25 and thecontacts 56 and 57 are separated when the armature poles are about torecede from the stator poles. In other words, the armature is so shapedand positioned with respect to the field structure 25 that the torqueproduced by the action of the field magnet upon the armature would bealternately clockwise and counterclockwise if the armature weremechanically rotated and the field structure were constantly excitedwithout any interruption of its excitation. It is for this reason thatthe contacts 56 and 57 are provided which are so interrelated by meansof the elliptical portion 35a of the crank shaft 35 that theenergization circuit for the field structure is opened at those timeswhen the torque tends to be negative with respect to the direction ofrotation. An impulse motor operates at a speed of the order of 8,000revolutions per minute and by virtue of the periodically operatedcontacts 56 and 57 operates equally well whether connected to a sourceof direct or a source of alternating current. i

For the purpose of preventing excessive arcing at the 4contacts 56 and57 and thereby to increase the contact life, there is included in theelectrical circuit as best :shown in Fig. 7 of the drawings a capacitor65 connected 'across the contacts 56 and 57, preferably through two`serially arranged identical resistors 66. The resistors 66 tend tolimit the magnitude of the discharge current of the capacitors 65 so asto reduce arcing when the charged capacitor 65 is suddenlyshort-circuited by closure of the contacts 56 and 57. Preferably, thecapacitor 65 and the resistors 66 are supported in the casing 11 in themanner disclosed in the above-mentioned copending Jepson and Cervenyapplication.

It will be understood that an impulse motor may have stopped in aposition such that no starting torque will be applied to the armature tocause rotation thereof and to this end such impulse motors are usuallyprovided with some manually actuable starting means. As illustrated inthe drawings, the casing 11 is provided with a suitable aperture 68through which may extend the manually engageable portion 69a of astarting lever 69 pivotally mounted as indicated at 70 to the bearingplates 29 and 30. The starting lever 69 is provided with a projection69b at the end thereof disposed within the casing 11 which tends tostress a torsion spring 71 wrapped around the pivot 70. This torsionspring has one end 71a anchored to a pin 72 projecting from the bearingplate 29. The other end of the torsion spring 71 designated as 71bextends in a direction toward the crank shaft 35 to which is attached asby suitable fastening means 7S a ratchet wheel 76. The torsion spring 71includes a lateral projection 71C which is adapted to engage the teethof the ratchet wheel 76 to rotate the same in a clockwise direction asviewed in Fig. of the drawings upon release of the starting lever 69,thereby giving the impulse motor an initial rotation suficient to startrotation.

From the above description, it will be apparent that there has beenprovided a simple and compact electric shaver with a greatly increasedcutting surface and cornprising relatively inexpensive parts which canbe assembled in a rapid and expeditious manner. The operation of theshaver embodying the invention can readily be understood in view of theabove description.

In Fig. 8 of the drawings there is illustrated a slight modification ofthe present invention in which the corresponding parts are designated bythe same reference numerals as in the preceding figures of the drawings.The difference between the arrangement disclosed in Fig. 8 and that ofthe preceding figures resides primarily in the means for transmittingthe driving force between the motor designated as f4 in Fig. 8 of thedrawings and the reciprocating cutters designated as 13 in Fig. 8 of thedrawings. In the preceding arrangements, the oscillating arms weredisposed so as to engage the cutters adjacent one end thereof whereas inFig. 8 the cutters 13 are provided with recesses 80 at the centerthereof for receiving therein the ends of the arms 40a of the lever 40.With this arrangement the motor is substantially reversed with thearmature adjacent the center of the casing and the winding 26 adjacentone end of the casing. If desired, instead of the starting lever shownin the preceding embodiments of the drawing, a suitable starting wheelmay be attached directly to an extension of the crank shaft 35 which mayprotrude at least partially through a suitable opening in the casing 11.

It will be understood that a relatively powerful motor is required inorder to reciprocate the cutters with the extensive cutting areaprovided therefor. Under these circumstances, a considerable amount ofheat produced in the field winding 26 must be dissipated. In Fig. 9 ofthe drawings, there is illustrated a modification of Fig. 8 in which asubstantially greater cutting area is provided by having the cuttingsurface along the longest dimension of the casing. Instead of having thetwo winding sections concentrated at one place, a more or less doublefield winding structure 81a and Sib is employed with windings 82 and 83disposed at the bight portions of the field structure and the armaturedisposed at the adjacent ends of the field structure remote fromwindings 82 and 83. With this arrangement, the windings 82 and 83 aredistributed with the consequent disabbassa *i skilled in the art.

1. 2, .j. y i I: tribution of heat produced therebyfsimplifyingthe motorcooling problem. The operation -of the 'arrangement disclosed 1n Fig. 9will readily be understood by those While there has been shownanddescribed particular embodiments of the present invention, it will beunderstood that other changes and modifications may obviously be made bythose skilled in the art without departing from the invention in itsbroader aspects, and it is desired in the appended claims to cover allsuch changes and modifications as fall within the true spirit and scopelcf the present invention.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:

1. An electric dry shaving device comprising a casing having a pair ofsubstantially parallel walls each of generally rectangularconfiguration, spaced from each other by a distance considerably lessthan the smallest dimension of said Walls, the dimensions of said casingbeing such to permit the device comfortably to be cupped in the hand ofthe operator and readily manipulated by such operator during a hairremoval operation, a cutting head extending substantially entirely alongone of the longest dimensions of said casing, a cutter movable inshearing engagement with the inside of said cutting head, a rotary motordisposed within said casing, means including a lever oscillatable abouta fixed pivot interconnecting said motor and said cutter, and a manuallyactuable starting mechanism pivotally mounted in said casing including aportion engageable with said motor to impart rotation thereto, andenergy storage means included in said starting mechanism.

2. An electric dry shaving device comprising a casing having a pair ofsubstantially parallel walls each of generally rectangularconfiguration, spaced from each other by a distance considerably lessthan the smallest dimension of said Walls, the dimensions of said casingbeing such to permit the device comfortably to be cupped in the hand ofthe operator and readily manipulated by such operator during a hairremoval operation, a cutting head extending substantially entirely alongone edge of said casing, a cutter movable in shearing engagement withthe inside of said cutting head, a relatively at rotary motor disposedwithin said casing with the axis of rotation of said motor extending inthe direction of the minimum dimension of said casing and perpendicularwith the longitudinal axis of said cutter, a bellcrank pivotally mountedwithin said casing drvingly interconnecting said motor and said cutter,a pivotal element mounted in said casing having a manually actuableportion thereof extending outside the casing, spring means supported insaid casing and engageable following stressing and release thereof withthe rotatable portion of said motor to impart a slight rotary motion tosaid rotatable portion, and means on said pivotal element for stressingsaid spring means.

3. An electric dry shaving device comprising a at rotary electric motorof the type having a U-shaped field structure with an armature rotatablebetween the ends of the arms of said U-shaped field structure and a coilsurrounding the bight portion of said structure, a casing for said motorincluding a pair of side walls each of generally rectangularconfiguration and spaced from each other by a distance considerably lessthan the shortest edge dimension of said wall, means for supporting saidmotor within said casing with the motor shaft extending between saidside walls and generally perpendicular thereto and with the arms of saidfield structure extending generally parallel with the longest dimensionof said walls whereby said casing for said motor has dimensions such asto permit the device comfortably to be cupped in the hand of theoperator and readily manipulated by such operator during a hair removingoperation, a cutting head extending substantially entirely along one ofthe long edges of said walls and generally parallel with said arms, acutter in shearing engagement with said cutting head and mounted forreciprocating movement longitudinally of said long edges of said walls,and means including a lever pivotally mounted to a xed pivot within saidcasing and oscillatable by said motor shaft and reciprocating saidcutter.

(References on following page) References Cited in the le of this patentUNITED STATES PATENTS Jepson Apr. 10, 1951 Florman Nov. 23, 1937 5Murphy Feb. 7, 1939 8 Hanley Oct. 17, 1939 Johnson et al Nov. 12, 1940Holsclaw July 6, 1943 Mehl July 6, 1943 Rand Mar. 7, 1944

